My 9n eats new points up in 10 mins

Badfish7

New User
I have a '39 9n that's been converted to 12v. I gutted the square can and made it pass-through and I'm running a round coil from a 80's F150. I'm getting no spark. So I change and set the points
(0.15) its gets spark, runs great for about 5-10 mins then dies, no spark. I take off the distributor and the new points I just set are shut and do not open when I turn the cam. They also don't
really line up correctly with each other. Even though these are new points I just installed, after that 10mins of running and then dying, there is no adjustment I can make to them to get them to open
again from the cam lobes.

So I thought maybe that this old distributor was worn out, so I got a new one from Complete Tractor. Inspected it out of the box, the points looked to be set correctly so I installed and fired the
tractor right up. After 10 mins of running, again, shuts off, no spark. I take the new distributor off and the exact same thing, points are not opening when you spin the cam. And the points do not
line up correctly, but they do touch. So I have rest the points now as best I could in the new distributor, and I'll try it again, but I'm pretty sure in 10mins it will die again with no spark and
when I pull the distributor. I'll find a set of points that don't open when I turn the cam.

What can be causing this???
 
" So I thought maybe that this old distributor was worn out"

Maybe it was. Or maybe it just needed bushings. Did you mic the wear parts to find out?


" the points looked to be set correctly "

What does that mean? Did you check the gap?

Is the wear block on the points wearing down?
75 Tips
 
An 80's Ford pkup would have electronic ignition and a very low-resistance primary winding, NOT a good choice to use with breaker points.

Are you using any type of ballast resistor with the coil?

Simplest fix would be to get a NAPA IC14-SB coil (or equivalent in another brand) "TRUE" 12 Volt coil that doesn't need a ballast resistor for use on 12 Volts. Less than $20, last I checked.
 
No, I didn't mic the wears parts, I'm pretty certain it was the original from 1939 so I just assumed a new one wouldn't hurt and I'd keep the old one for parts and such.

When said the points looked to be set correctly, I spun the cam to see if they opened and shut like they were supposed to, they did. Then I used a 0.015 feeler gauge to make sure the gap was correct, it was. But I noticed that even new out of the box, the points contacts don't directly line up with each other. I rest the points on the new distributor, and attached some pics, see how far off of each other they are? why is that? are they low quality points or something?
a281068.jpg

a281069.jpg
 
Looks like your points have thermoplastic "wear blocks" vs. phenolic "wear blocks" that (at least used to be) the mark of better-quality point sets, and that point overheating has softened the plastic neat the point and allowed the force of the flat steel spring to tip the contact point out of position.

You still haven't told us if you are using some type of primary resistor.

Also, a measurement of primary current draw would be helpful.
 
Compare a brand-new set of points with a used set that no longer works (the same brand and source). What appears to be different?

The rubbing block?

The contacts?

Something else?
 
Thanks for all help here guys, really appreciate. The 6v to 12v conversion was done before I go it, it however was using the 12v square can coil, and after two of them failed after about 10hours of use, I opted to gut one out and use a 12v round coil. There is a ballast resistor present, it looks like this: https://shop.advanceautoparts.com/p/bwd-ignition-coil-resistor-ru4/5260809-p?c3ch=PLA&c3nid=5260809-P&adtype=pla_with_promotion&gclid=Cj0KCQjw3KzdBRDWARIsAIJ8TMQRKi0zJtsDoIxerTGybWsx1l26oKCA4VPd8Jd7IqXvFP7Iwa-j2w0aAmAuEALw_wcB&gclsrc=aw.ds&dclid=CN6w9_il2d0CFQNswQodoQIMtgj2w0aAmAuEALw_wcB&gclsrc=aw.ds&dclid=CN6w9_il2d0CFQNswQodoQIMtg



If that link doesn't work I've attached a pic also.
 
If it is that exact resistor, it's listed as .75 to 1.5 Ohms, which, likely isn't enough resistance when used with a coil from a factory EI system.

If you could measure the primary Amps accurately, that would tell the tale... conventional wisdom is that if less than 3 Amps, the spark will be likely weak, as you approach and exceed 4 Amps, you are entering the coil and points heating/damage area.

This is measured with a fully-charged battery, switch "ON", points closed, and (obviously) engine not running.
 
It?s your tractor and your $$$ so you can do anything you want with it. That being said, if you do indeed have a true 1939 9N, if?N it were me, I?d be restoring it as all original. It never ceases to amaze me why fellers try to re-invent the wheel by going to extremes with ?conversions? like you state. I?m not talking about a standard 12V conversion, there?s nothing wrong with that if done for the right reasons. Burning up points in 10 minute should be a huge clue the wiring is all wrong. 99.98% of all non-starting/non-running issues are due to poor/incorrect/mucked-up wiring jobs regardless if they are 6V or 12V. These N?s will operate just fine with the original electrical setup. The key is to keep them properly maintained. These N?s were designed so major parts could be rebuilt over and over, the distributors are one of them. I bought an aftermarket unit once about 15 years ago from a well-known franchise store and it was junk. Never again. I rebuild the originals all the time now. I don?t know nor care who Complete Tractor is, but there are but a handful of quality parts suppliers around. Your point gap on a front mount distributor is .015?, not .15? as you listed. I hope you know the difference. You?re far better ahead rebuilding a ?worn? distributor, if it was as you say, a WAG really. The slop is usually due to worn bushings and cam weights ?all replaceable. Why don?t you get out your essential manuals and perform a root cause problem solving procedure rather than ?guess? and ?surmise? things will fail again and again? Like I said, if it were me, Id scrap the 80?s F-150 setup and go back to the basic original or at least wire it correctly for a 12V switch over job. The 1939 9N used a small generator with a square Voltage Regulator. You probably don?t have those if all that you say has been done. Front Mount Distributor 12V conversion uses: 12V battery NEG/GND; no genny or VR; original ballast resistor wired as OEM 6V system; 6V coil with external ceramic 1-OHM resistor, or a 12V coil an NO external resistor; ammeter (some opt for a Voltmeter with 12V), key switch; neutral safety starter button; 1-wire starter motor -all wired correctly.

9N/2N WIRING:
QWaC1aah.jpg
iP09xMVh.jpg

Tim Daley(MI)
 
Thanks for the diagrams Tim, I am going to rewire it over the winter and this will be very helpful as don't have my manual on this one yet.
 
What you said Bob is exactly what was happening, the 'cheap' points were overheating from the Ford coil. I got the correct coil and some good points from NAPA and its seems to have fixed the 'dying in 10 mins' problem. I have another problem now however, timing. Its popping and cracking at full throttle and has no power, even though it runs smooth at low/idle. When I got the new distributor, I set the timing using the method of using two straight edges (see attached pic). The problem I have is that when I have the straight edge on the 'wide' side of the shaft, I cannot get the straight edge to come 1/4in off the hole? with the timing plate and lock screw in the extreme 'up' position (as far as it will go), I can only get about 3/16 off the edge of the hole? what am I doing wrong?

mvphoto24294.jpg
 
(quoted from post at 19:57:33 09/27/18) What you said Bob is exactly what was happening, the 'cheap' points were overheating from the Ford coil. I got the correct coil and some good points from NAPA and its seems to have fixed the 'dying in 10 mins' problem. I have another problem now however, timing. Its popping and cracking at full throttle and has no power, even though it runs smooth at low/idle. When I got the new distributor, I set the timing using the method of using two straight edges (see attached pic). The problem I have is that when I have the straight edge on the 'wide' side of the shaft, I cannot get the straight edge to come 1/4in off the hole? with the timing plate and lock screw in the extreme 'up' position (as far as it will go), I can only get about 3/16 off the edge of the hole? what am I doing wrong?

mvphoto24294.jpg
on't worry about it. that 1/16th is a degree and a half. there is more slop than that everywhere else in the system. As soon as you start it and the points gap changes by 0.002", then your timing will have changed by that same 1.5 degrees.
 
Have you determined if it is indeed an early 1939 9N? There are several identifiers for each model year. You do know that ALL 9N and 2N models have the "9N" prefix in the serial number, right? 9N's made '39-'42; 2N's made '42 thru '47. Technically, in February, 1947 all 2N tractor production came to an end. Henry Ford II had fired Harry Ferguson so he was no longer with the company, was gone months, almost a year earlier. FORD was retooling everything for the new model, the '8N', first released in July, 1947. The '8' was to identify it for the new model year, 1948. Technically, all 8Ns built in '47 are considered, and should be ID'd as 1948 models. My early 8N with a 5-digit s/n and the "I167" engine casting code date designates the block was cast on September 16, 1947. Though many systems are the same if not similar on the 9N/2N and the 8N, there are a few that are not. The hydraulics are different -the 8N has POSITION CONTROL in addition to DRAFT CONTROL and, the 8N has a 4-speed transmission to name two of the major differences. You can find original copies of the manuals on the auction sites and tractor ads forums, or buy new reproduction copies at most parts suppliers. The I&T F-04 manual, the 39-53 MPC (Master Parts Catalog) and 9N/2N Operator & Service manuals are great tools. There are specific model year MPC's as well that will pinpoint what parts were originally used. Some parts have been superseded over the years, especially in the electrical system, and now there may be only one generic unit used, like the generator. The 5 manuals as shown on the left in my picture are valuable tools -get them.

FORD 9N/2N ESSENTIAL OWNER/OPERATOR/PARTS/SERVICE MANUALS:
i2gbSeoh.jpg

9N/2N WIRING DIAGRAM, AFTER S/N 12500:
QWaC1aah.jpg


TPD
 
Thanks Jmor, curious then why the timing plate and lock screw have to go into the extreme end of the 'up' position to be correct? In all my past experience when you're at the extreme end of an
adjustment range on something, its usually because its worn or degraded from its original spec. That doesn't really apply here, as this is a 'set it and forget it' situation. Why would they make the
adjustment range where it is when you have to go all the way to one end of it? Why are the other positions on the timing plate and lock screw even be available?
 
(quoted from post at 11:15:59 09/28/18) Thanks Jmor, curious then why the timing plate and lock screw have to go into the extreme end of the 'up' position to be correct? In all my past experience when you're at the extreme end of an
adjustment range on something, its usually because its worn or degraded from its original spec. That doesn't really apply here, as this is a 'set it and forget it' situation. Why would they make the
adjustment range where it is when you have to go all the way to one end of it? Why are the other positions on the timing plate and lock screw even be available?

IMHO, the adjustment is to make up of for slight errors in manufacturing tolerances, and POSSIBLY to compensate for advance mechanism wear.

It seems like your modern reproduction distributor has rather severe "slight errors in manufacturing tolerances", SO typical of replacement parts nowadays for this older stuff.
 
I would have come to the same conclusion, however my old original distributor is exactly the same way. Timing adj plate and lock screw in the extreme 'up' position gets me 3/16 off the hole. It moves
the whole plate so far counter clockwise that the brass screw that should be at approx 12 o'clock is at about 11:30 and I am concerned that the 'pigtail' on the bottom of the square can will miss it.
 
(quoted from post at 14:22:33 09/28/18) I would have come to the same conclusion, however my old original distributor is exactly the same way. Timing adj plate and lock screw in the extreme 'up' position gets me 3/16 off the hole. It moves
the whole plate so far counter clockwise that the brass screw that should be at approx 12 o'clock is at about 11:30 and I am concerned that the 'pigtail' on the bottom of the square can will miss it.
have seen that , where pig tail contact is lost at extreme. Best to mount coil on distr before installing assy on engine so that you can see contact point.
 

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